Medication delivery device including disposable and reusable portions

ABSTRACT

A medication delivery device includes a disposable portion and a reusable portion. The disposable portion includes a therapeutic agent delivery assembly, and the therapeutic agent delivery assembly includes a needle. The therapeutic agent delivery assembly is translatable from a stowed configuration to a deployed configuration. The reusable portion includes a first rack and pinion mechanism and a second rack and pinion mechanism. The first rack and pinion mechanism is actuatable to translate the therapeutic agent delivery assembly from the stowed configuration to the deployed configuration. The second rack and pinion mechanism is actuatable to translate a plunger and thereby cause the therapeutic agent delivery assembly to deliver a therapeutic agent from the needle.

BACKGROUND

The present disclosure pertains to medication delivery devices, and, inparticular, to a portable medication delivery device such as an injectorpen.

Patients suffering from a number of different diseases frequently mustinject themselves with medication. To allow a person to conveniently andaccurately self-administer medicine, a variety of devices broadly knownas injector pens or injection pens have been developed. Generally, thesepens are equipped with a cartridge including a piston and one or moredoses of liquid medication. A drive member, extending from within a baseof the injector pen and operably connected with typically more rearwardmechanisms of the pen that control drive member motion, is movableforward to advance the piston in the cartridge in such a manner todispense the contained medication from an outlet at the oppositecartridge end, typically through a needle that penetrates a stopper atthat opposite end. In disposable pens, after a pen has been used andexhausted the supply of medication within the cartridge, the entire penis discarded by a user, who may then begin using a replacement pen. Inreusable pens, after a pen has been used and exhausted the supply ofmedication within the cartridge, the pen is disassembled, the spentcartridge is replaced with a fresh cartridge, and the pen is reassembledfor its subsequent use.

It would be desirable to provide a medication delivery device withimproved features, such as a providing a reusable device thatfacilitates ease of replacement of a spent cartridge with a freshcartridge and reduces the size and/or the number of components of thespent cartridge to reduce waste.

SUMMARY

According to an embodiment of the present disclosure, a medicationdelivery device is provided. The medication delivery device includes adisposable portion and a reusable portion. The disposable portionincludes a housing having a distal end and a therapeutic agent deliveryassembly carried by the housing. The therapeutic agent delivery assemblyincludes a chamber including a passageway, a therapeutic agent carriedin the passageway, and a needle in communication with the passageway.The therapeutic agent delivery assembly is translatable relative to thehousing from a stowed configuration to a deployed configuration, in thestowed configuration the needle is disposed proximally relative to thedistal end of the housing, and in the deployed configuration the needleat least partially extends distally from the distal end of the housing.The reusable portion includes a housing and a drive mechanism carried bythe housing of the reusable portion. The drive mechanism includes afirst rack and pinion mechanism and a frame translatably carried by thehousing of the reusable portion via the first rack and pinion mechanism.The drive mechanism further includes a second rack and pinion mechanismcoupled to the frame and a plunger translatably carried by the frame viathe second rack and pinion mechanism. The first rack and pinionmechanism is actuatable to translate the frame relative to the housingof the reusable portion, and the frame thereby translates thetherapeutic agent delivery assembly relative to the housing of thedisposable portion from the stowed configuration to the deployedconfiguration. The second rack and pinion mechanism is actuatable totranslate the plunger relative to the frame, the plunger thereby causesthe therapeutic agent delivery assembly to deliver the therapeutic agentfrom the needle.

According to another embodiment of the present disclosure, a method fordelivering a therapeutic agent from a medication delivery device to apatient is provided. The medication delivery device includes a reusableportion and a disposable portion that is detachably carried by thereusable portion, and the disposable portion carries the therapeuticagent. The method includes positioning a distal end of the disposableportion adjacent to the skin of the patient, and a needle of thedisposable portion is disposed proximally relative to the distal end ofthe disposable portion. The method further includes actuating a firstrack and pinion mechanism of the reusable portion to thereby drive theneedle relative to the distal end of the disposable portion such thatthe needle at least partially extends distally from the distal end ofthe disposable portion and pierces the skin of the patient. The methodfurther includes actuating a second rack and pinion mechanism of thereusable portion to thereby cause the disposable portion to deliver thetherapeutic agent from the needle to the patient.

According to yet another embodiment of the present disclosure, adisposable portion for a medication delivery device is provided. Themedication delivery device includes a reusable portion that isconfigured to detachably carry the disposable portion. The disposableportion includes a housing having a distal end and a therapeutic agentdelivery assembly translatably carried in the housing. The therapeuticagent delivery assembly includes a chamber having a passageway, atherapeutic agent carried in the passageway, and a needle incommunication with the passageway. A biasing element is carried in thehousing, and the biasing element biases the therapeutic agent deliveryassembly toward a stowed configuration. In the stowed configuration theneedle is disposed proximally relative to the distal end of the housing.A proximal cover is carried by the housing. The proximal cover retainsthe therapeutic agent delivery assembly in the housing, and the proximalcover includes a securing feature that is configured to detachablysecure the disposable portion to the reusable portion. The therapeuticagent delivery assembly is translatable by the reusable portion relativeto the housing from the stowed configuration to a deployedconfiguration. In the deployed configuration the needle at leastpartially extends distally from the distal end of the housing.

According to yet another embodiment of the present disclosure, a driveportion of a medication delivery device is provided. The drive portionincludes a housing and a drive mechanism carried by the housing. Thedrive mechanism includes a first rack and pinion mechanism, and a frametranslatably carried by the housing via the first rack and pinionmechanism. Also includes is a second rack and pinion mechanism coupledto the frame, and a plunger translatably carried by the frame via thesecond rack and pinion mechanism. The first rack and pinion mechanism isactuatable to translate the frame relative to the housing configured totranslate a therapeutic agent delivery assembly from a stowedconfiguration to a deployed configuration. The second rack and pinionmechanism is actuatable to translate the plunger relative to the frameto deliver a therapeutic agent from a needle of the therapeutic agentdelivery assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other advantages and objects of this invention,and the manner of attaining them, will become more apparent, and theinvention itself will be better understood, by reference to thefollowing description of embodiments of the invention taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a medication delivery device accordingto an embodiment of the present disclosure.

FIG. 2 is a side view of the medication delivery device of FIG. 1 .

FIG. 3 is a side view of a reusable portion of the medication deliverydevice of FIG. 1 .

FIG. 4 is an exploded perspective view of the reusable portion of FIG. 3.

FIG. 5 is a perspective view of a first housing portion of the reusableportion of FIG. 3 .

FIG. 6 is a side view of the first housing portion of FIG. 5 .

FIG. 7 is a perspective view of a second housing portion of the reusableportion of FIG. 3 .

FIG. 8 is a side view of the second housing portion of FIG. 7 .

FIG. 9 is a perspective view of a frame and first and second actuatorsof the reusable portion of FIG. 3 .

FIG. 10 is another perspective view of the frame and the first andsecond actuators of FIG. 9 .

FIG. 11 is a perspective view of a plunger of the reusable portion ofFIG. 3 .

FIG. 12 is a schematic representation of an electronics assembly of thereusable portion of FIG. 3 .

FIG. 13 is a side view of a disposable portion of the medicationdelivery device of FIG. 1 .

FIG. 14 is an exploded side view of the disposable portion of FIG. 13 .

FIG. 15 is a top perspective view of a proximal cover of the of thedisposable portion of FIG. 13 .

FIG. 16 is a bottom perspective view of the proximal cover of FIG. 15 .

FIG. 17 is a side view of a therapeutic agent delivery assembly of thedisposable portion of FIG. 13 .

FIG. 18 is a longitudinal sectional view of the therapeutic agentdelivery assembly along line 18-18 of FIG. 17 .

FIG. 19 is a side view of a housing of the disposable portion of FIG. 13.

FIG. 20 is a longitudinal sectional view of the housing along line 20-20of FIG. 19 .

FIG. 21 is a top perspective view of a baseplate of the disposableportion of FIG. 13 .

FIG. 22 is a bottom perspective view of the baseplate of FIG. 21 .

FIG. 23 is a longitudinal sectional view of the baseplate along line23-23 of FIG. 22 .

FIG. 24 is an exploded perspective view of a base portion of thedisposable portion of FIG. 13 .

FIG. 25 is another exploded perspective view of the base portion of FIG.24 .

FIG. 26 is a perspective view of an alternative shield puller for thebase portion of FIG. 24 .

FIG. 27 is a perspective view of an alternative basecap for the baseportion of FIG. 24 .

FIG. 28 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 before coupling the disposable portion to the reusableportion.

FIG. 29 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon coupling the disposable portion to the reusableportion.

FIG. 30 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon detaching the base portion from the disposableportion.

FIG. 31 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon abutting the skin of a patient and actuating auser input of the device.

FIG. 32 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon deploying a needle from the device and piercingthe skin of the patient.

FIG. 33 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon delivering a therapeutic agent to the patient viathe needle.

FIG. 34 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon retracting the needle from the patient.

FIG. 35 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 upon retracting the plunger from the therapeutic agentdelivery assembly.

FIG. 36 is a longitudinal sectional view of the medication deliverydevice of FIG. 1 while detaching the disposable portion from thereusable portion.

FIG. 37 is a partial longitudinal sectional view of the medicationdelivery device of FIG. 1 after detaching the disposable portion fromthe reusable portion.

Corresponding reference characters indicate corresponding partsthroughout the several views. Although the drawings representembodiments of the present invention, the drawings are not necessarilyto scale, and certain features may be exaggerated or omitted in some ofthe drawings in order to better illustrate and explain the presentinvention.

DETAILED DESCRIPTION

Any directional references used with respect to any of the Figures, suchas right or left, up or down, or top or bottom, are intended forconvenience of description, and does not limit the present disclosure orany of its components to any particular positional or spatialorientation.

FIGS. 1 and 2 illustrate a medication delivery device 10 according to anexemplary embodiment of the present disclosure. Illustratively, themedication delivery device 10 has an injector pen-like shape, althoughother shapes may alternatively be used. The medication delivery device10 generally includes a reusable portion 12, which may also be referredto as a drive portion, and a disposable portion 14, which may also bereferred to as a drug carrying portion. The reusable portion 12facilitates delivery of a therapeutic agent (shown elsewhere) from thedisposable portion 14. In addition, the reusable portion 12 detachablycouples to the disposable portion 14 such that after the therapeuticagent has been delivered from the disposable portion 14, the disposableportion 14 may be detached from the reusable portion 12 and discarded.Another disposable portion (not shown—for example, having the same ordifferent features than the disposable portion 14) may then be attachedto the reusable portion 12, and the medication delivery device 10 isthereby ready for subsequent use. In one embodiment, the reusableportion 12 and the disposable portion 14 may be permanently secured toone another to define a disposable device.

The medication delivery device 10 also includes a proximal end 16 and anopposite distal end 18. During use of the medication delivery device 10,the proximal end 16 would be farther from the patient and configured tobe actuated by the user, and the distal end 18 would be closer to thepatient and configured to deliver the therapeutic agent (shownelsewhere) to the patient. The medication delivery device 10 alsoincludes a longitudinal axis A extending between the proximal end 16 andthe distal end 18. These and other features of the medication deliverydevice 10 are described in further detail below.

FIGS. 3 and 4 illustrate the reusable portion 12 of the medicationdelivery device 10. With specific reference to the exploded view of FIG.4 , the reusable portion 12 generally includes a housing 20 that carriesa drive mechanism 22, a biasing element 24 (illustratively, acompression spring), and a user input or button 26. The reusable portion12 further includes an electronics assembly (shown elsewhere) thatfacilitates actuating the drive mechanism 22.

The housing 20 illustratively includes a first housing portion 28 and asecond housing portion 30 that carry the drive mechanism 22. The housing20 further includes a third housing portion 32 that carries the userinput 26. Illustratively, the drive mechanism 22 includes a frame 34that is translatably carried by the housing 20 and a plunger 36 that istranslatably carried by the frame 34. The drive mechanism 22 furtherincludes a first rack and pinion mechanism 38 (only partially visible inFIG. 4 ) and a second rack and pinion mechanism 40. The first rack andpinion mechanism 38 and the second rack and pinion mechanism 40 areactuatable to drive the frame 34 relative to the housing 20 and theplunger 36 relative to the frame 34, respectively, to facilitatedelivery of the therapeutic agent from the medication delivery device10. The housing 20, the drive mechanism 22, and other features of thereusable portion 12 of the medication delivery device 10 are describedin further detail below. In one embodiment the device includes one ofthe first or second rack and pinion mechanisms and another mechanismthat is not a rack and pinion may be used for the syringe drive andplunger drive, such as a spring drive, a rotary or linear electric motordrive, chemical reaction drive, or the like.

FIGS. 5 and 6 illustrate the first housing portion 28 of the housing 20.The first housing portion 28 includes an external surface 42 and anopposite internal surface 44. The internal surface 44 partially definesan inner chamber 46 that receives the drive mechanism 22 (shownelsewhere). The internal surface 44 also defines a first rack 48 of thefirst rack and pinion mechanism 38 (shown elsewhere). Stated anotherway, the first housing portion 28 and the first rack 48 aremonolithically formed with each other. The first housing portion 28further includes upper and lower coupling surfaces 50 on opposite sidesof the internal surface 44. The coupling surfaces 50 each include one ormore coupling features 52 (illustratively, a plurality of threadedholes) that facilitate coupling the first housing portion 28 to thesecond housing portion 30 (shown elsewhere). In other embodiments,different arrangements of the first housing portion 28 are possible. Forexample, the first housing portion 28 and the first rack 48 may beformed separately, and the first rack 48 may be coupled to the internalsurface 44 of the first housing portion 28 via, for example, one or morefasteners (not shown) and/or adhesives (not shown).

FIGS. 7 and 8 illustrate the second housing portion 30 of the housing20. The second housing portion 30 includes an external surface 54 and anopposite internal surface 56. The internal surface 56 defines, togetherwith the first housing portion 28 (shown elsewhere), the inner chamber46 that receives the drive mechanism 22 (shown elsewhere). The internalsurface 56 also defines a translation feature 58 that facilitatestranslatably carrying the frame 34. Stated another way, the secondhousing portion 30 and the translation feature 58 are monolithicallyformed with each other. Illustratively, the translation feature 58 isprovided as an elongated protrusion. The second housing portion 30further includes upper and lower coupling surfaces 60 on opposite sidesof the internal surface 56. The coupling surfaces 60 each include one ormore coupling features 62 (illustratively, a plurality of apertures forreceiving threaded fasteners—not shown) that facilitate coupling thesecond housing portion 30 to the first housing portion 28. The secondhousing portion 30 further includes a coupling portion 64 for detachablysecuring the reusable portion 12 to the disposable portion 14 (shownelsewhere). Illustratively, the coupling portion 64 includes acylindrical wall 66 for receiving the disposable portion 14 and aplurality of securing features 68 (one of which is shown in FIG. 7 ) forsecuring the disposable portion 14 to the reusable portion 12. Thesecuring features 68 may provide a bayonet-like or “twist-to-lock”connector; more specifically, the securing features 68 may be generallyL-shaped protrusions. In other embodiments, different arrangements ofthe second housing portion 30 are possible. For example, the secondhousing portion 30 and the translation feature 58 may be formedseparately, and the translation feature 58 may be coupled to theinternal surface 56 of the second housing portion 30 via, for example,one or more fasteners (not shown) and/or adhesives (not shown). Asanother example, instead of providing the translation feature 58 as apositive feature (illustratively, the elongated protrusion), thetranslation feature 58 could be a negative feature (for example, anelongated slot—not shown). Other kinds of securing features 68 may beused, such as, for example, a flexing tab-in-slot connection, a threadedconnection, a magnetic connection, or a key-in-slot connection.

FIGS. 9 and 10 partially illustrate the drive mechanism 22 of thereusable portion 12 of the medication delivery device 10. Morespecifically, FIGS. 9 and 10 illustrate the frame 34, a first actuator70 of the first rack and pinion mechanism 38 (shown elsewhere), and asecond actuator 72 of the second rack and pinion mechanism 40 (shownelsewhere). The frame 34 includes a first mounting portion 74 thatcarries the first actuator 70 and a second mounting portion 76 thatcarries the second actuator 72. Opposite the first mounting portion 74and the second mounting portion 76, the frame 34 further includes atranslation feature 78 that couples to the translation feature 58 of thesecond housing portion 30 (shown elsewhere). Illustratively, thetranslation feature 58 is provided as an elongated slot. The frame 34further includes a plunger aperture 80 that translatably receives theplunger 36 (shown elsewhere). In other embodiments, differentarrangements of the frame 34 are possible. For example, instead ofproviding the translation feature 78 as a negative feature(illustratively, the elongated slot), the translation feature 78 couldbe a positive feature (for example, an elongated protrusion—not shown).

With continued referenced to FIGS. 9 and 10 , the first actuator 70includes a first motor 82 (for example, a stepper motor) that is carriedby the first mounting portion 74 of the frame 34. The first actuator 70further includes a first pinion 84 that is rotatably driven byenergizing the first motor 82. The first pinion 84 drivingly engages thefirst rack 48 of the first rack and pinion mechanism 38 (shownelsewhere). As such, energizing the first motor 82 causes the firstpinion 84 to rotate and drive the first rack 48, which causes the frame34 to translate relative to the housing 20 (both shown elsewhere).Similarly, the second actuator 72 includes a second motor 86 (forexample, a stepper motor) that is carried by the second mounting portion76 of the frame 34. The second actuator 72 further includes a secondpinion 88 that is rotatably driven by energizing the second motor 86.The second pinion 88 drivingly engages a second rack of the second rackand pinion mechanism 40 (shown elsewhere), which, as described infurther detail below, is coupled to the plunger 36 (shown elsewhere). Assuch, energizing the second motor 86 causes the second pinion 88 torotate and drive the second rack, which causes the plunger 36 totranslate relative to the frame 34.

FIG. 11 illustrates the plunger 36 of the reusable portion 12 of themedication delivery device 10. The plunger 36 includes an elongatedshaft 92, and a side of the shaft 92 defines the second rack 90 of thesecond rack and pinion mechanism 40 (shown elsewhere). Stated anotherway, the shaft 92 and the second rack 90 are monolithically formed witheach other. The shaft 92 terminates at a distal end 94. The distal end94 is configured to engage and actuate the disposable portion 14 (shownelsewhere) and thereby facilitate delivering the therapeutic agent fromthe disposable portion 14, as described in further detail below. Inother embodiments, different arrangements of the plunger 36 arepossible. For example, the plunger 36 and the second rack 90 may beformed separately, and the second rack 90 may be coupled to the plunger36 via, for example, one or more fasteners (not shown) and/or adhesives(not shown).

FIG. 12 illustrates the electronics assembly 96 of the reusable portion12 of the medication delivery device 10. The electronics assembly 96includes an electronic controller 98 that is operatively coupled to andreceives power from a power supply 100 (illustratively, a battery). Theelectronic controller 98 operatively couples to the user input 26.Actuation of the user input 26 (for example, depressing the user input26) may cause the user input 26 to send an actuation signal to theelectronic controller 98 (for example, by closing an electricalcircuit). The electronic controller 98 also operatively couples to thefirst actuator 70 and the second actuator 72. Upon receiving theactuation signal from the user input 26, the electronic controller 98may energize the first actuator 70 and the second actuator 72 (forexample, sequentially, as described in further detail below). In otherembodiments, the electronics assembly 96 may take other forms. Forexample, the electronics assembly 96 and the electronic controller 98may operatively couple to and receive power from an external powersupply (not shown—for example, a wall outlet).

FIGS. 13 and 14 illustrate the disposable portion 14 of the medicationdelivery device 10. With specific reference to the exploded view of FIG.14 , the disposable portion 14 generally includes a housing 102 thatcarries a coupling element or proximal cover 104, a biasing element 106(illustratively, a compression spring), a therapeutic agent deliveryassembly 108, a baseplate 110, and a base portion 112.

FIGS. 15 and 16 illustrate the proximal cover 104 of the disposableportion 14 of the medication delivery device 10. The proximal cover 104includes a main body 114 that has a generally cylindrical shape. Themain body 114 includes an inner passageway 116 that receives othercomponents, including the biasing element 106 and the therapeutic agentdelivery assembly 108 of the disposable portion 14 (both shownelsewhere) and the plunger 36 of the reusable portion 12 (shownelsewhere). An inner surface 118 of the proximal cover 104 carries abiasing platform 120 (illustratively, a radially-inwardly extendingflange) that inhibits the therapeutic agent delivery assembly 108 fromextending proximally through the inner passageway 116. The inner surface118 also includes a coupling feature 122 (illustratively, a threadedsurface) for coupling the proximal cover 104 to the housing 102 (shownelsewhere). An outer surface 124 of the proximal cover 104 also includesa plurality of securing features 126 for selectively coupling to thesecuring features 68 of the reusable portion 12 (shown elsewhere) andthereby selectively securing the disposable portion 14 to the reusableportion 12. The securing features 126 may provide a bayonet-like or“twist-to-lock” connector; more specifically, the securing features 126may be generally L-shaped recesses. In other embodiments, differentarrangements of the proximal cover 104 are possible. For example, thecoupling feature 122 may be a welded connection to the housing 102.

FIGS. 17 and 18 illustrate the therapeutic agent delivery assembly 108of the disposable portion 14 of the medication delivery device 10. Thetherapeutic agent delivery assembly 108 includes a syringe chamber 128,and the syringe chamber 128 includes a syringe passageway 130 that has aproximal opening 132. The proximal opening 132 receives the plunger 36of the disposable portion 14 (shown elsewhere). The syringe passageway130 carries a piston 134, and the piston 134 translates away from theproximal opening 132 and towards an outlet portion 136 of thetherapeutic agent delivery assembly 108 when the plunger 36 is driven bythe drive mechanism 22 of the reusable portion 12 (shown elsewhere). Thesyringe passageway 130 also carries the therapeutic agent 138(illustratively, 1 mL of the therapeutic agent 138, although othervolumes, including, for example, 0.5 mL, 1.5 mL, 1.75 mL, 2 mL, 2.25 mL,or 2.5 mL may alternatively be carried) between the piston 134 and theoutlet portion 136, more specifically a needle 140. As such, translationof the piston 134 in the syringe passageway 130 causes the needle 140 todischarge the therapeutic agent 138 therefrom. The therapeutic agentdelivery assembly 108 further includes a proximal stop element 142(illustratively, a semi-annular ring) that is carried by the syringechamber 128 adjacent to the proximal opening 132. The proximal stopelement 142 includes a distal side 144 that abuts the biasing element106 (shown elsewhere), and the biasing element 106 thereby urges anopposite proximal side 146 of the proximal stop element 142 to abut thebiasing platform 120 of the proximal cover 104 (shown elsewhere). Thetherapeutic agent delivery assembly 108 further includes a distal stopelement 148 (illustratively, a semi-annular sleeve) that is carried bythe syringe chamber 128 adjacent to the outlet portion 136. The distalstop element 148 abuts the baseplate 110 (shown elsewhere) to limitdistal translation of the therapeutic agent delivery assembly 108relative to the baseplate 110. In other embodiments, differentarrangements of the therapeutic agent delivery assembly 108 arepossible. For example, the therapeutic agent delivery assembly 108 couldbe replaced by or include another type of therapeutic agent container,such as a bellows or bladder structure.

Medication delivery devices according to the present disclosure carryand dispense one or more therapeutic agents, which may also be referredto as medications or drugs. Such therapeutic agents 138 may include, forexample, epinephrine, anesthetics, analgesics, steroids, insulins,insulin analogs, insulin derivatives, GLP-1 receptor agonists such asdulaglutide or liraglutide, glucagon, glucagon analogs, glucagonderivatives, gastric inhibitory polypetide (GIP), GIP analogs, GIPderivatives, combined GIP/GLP-1 agonists such as tirzepatide,oxyntomodulin analogs, oxyntomodulin derivatives, basal insulins,therapeutic antibodies, which may include IL-17A antagonist such asixekizumab, calcitonin-gene related peptide anatagonist such asgalcanezumab, IL-13 monoclonal antibody such as lebrikizumab, IL-23antibody such as mirikizumab, IL-2 conjugate, PD-1 antibody agonist,ramucirumab or other cancer treatments, or any other therapeutic agentthat is capable of delivery by devices according to the presentdisclosure. Medication delivery devices according to the presentdisclosure are operated in a manner generally as described herein by auser (for example, a healthcare professional, a caregiver, or anotherperson) to deliver one or more therapeutic agents to a patient (forexample, another person or the user).

FIGS. 19 and 20 illustrate the housing 102 of the disposable portion 14of the medication delivery device 10. The housing 102 includes a mainbody 150 that has a generally cylindrical shape that flares outwardly atthe distal end 18. The main body 150 includes an inner passageway 152that carries other components of the disposable portion 14, specificallythe therapeutic agent delivery assembly 108, the biasing element 106,the baseplate 110, and the base portion 112 (all shown elsewhere).Adjacent to the inner passageway 152, an inner surface 154 of thehousing 102 carries a biasing platform 156 (illustratively, aradially-inwardly extending flange) that abuts the biasing element 106(shown elsewhere). As such, the housing 102 carries the biasing element106 between the biasing platform 156 and the proximal stop element 142of the therapeutic agent delivery assembly 108 (shown elsewhere).Externally and at a proximal end 158, the housing 102 further includes acoupling feature 160 (illustratively, a threaded surface) for couplingto the proximal cover 104 (shown elsewhere), and the proximal cover 104retains the therapeutic agent delivery assembly 108 in the innerpassageway 152 of the housing 102. In other embodiments, differentarrangements of the housing 102 are possible. For example, the couplingfeature 160 may be a welded connection to the proximal cover 104. Asanother example, the housing 102 may have a non-flaring shape at thedistal end 18.

FIGS. 21-23 illustrate the baseplate 110 of the disposable portion 14 ofthe medication delivery device 10. The baseplate 110 includes a mainbody 162 that has a generally cylindrical shape with an outwardlyextending flange 164 at the distal end 18. The main body 162 includes aninner passageway 166 that carries other components of the disposableportion 14, specifically the therapeutic agent delivery assembly 108 andthe base portion 112 (both shown elsewhere). Adjacent to the innerpassageway 166, an inner surface 168 of the baseplate 110 carries a stopelement 170 (illustratively, a radially-inwardly extending flange) thatabuts the distal stop element 148 of the therapeutic agent deliveryassembly 108 (shown elsewhere) to limit distal translation of thetherapeutic agent delivery assembly 108 relative to the baseplate 110. Adistal portion 172 of the inner surface 168 also carries one or moreguard features 174 (illustratively, a plurality of elongated ridges,more specifically three ridges) that inhibit objects (such as afingertip of the user or patient) from entering the inner passageway 166and contacting the needle 140 of the therapeutic agent delivery assembly108 (shown elsewhere). In other embodiments, other arrangements of thebaseplate 110 are possible. For example, the baseplate 110 may lack theoutwardly extending flange 164 at the distal end 18.

FIGS. 24 and 25 illustrate the base portion 112 of the disposableportion 14 of the medication delivery device 10. The base portion 112 isinitially and detachably carried at the distal end 18 of the disposableportion 14. The base portion 112 includes a needle shield 176, which mayalso be referred to as a rigid needle shield, a shield puller 178, and abasecap 180. The needle shield 176 initially covers and maintainssterility of the needle 140 of the therapeutic agent delivery assembly108 (shown elsewhere). The shield puller 178 couples the needle shield176 to the basecap 180 and facilitates separating the needle shield 176from the needle 140 upon detaching the basecap 180 from the housing 102(shown elsewhere). The basecap 180 initially obscures the innerpassageway 166 of the baseplate 110 (shown elsewhere) and retains theshield puller 178 and the needle shield 176 adjacent to the needle 140.The base portion 112 may be appropriate for use with a medicationdelivery device 10 carrying a specific volume of the therapeutic agent138, such as 1 mL of the therapeutic agent 138. The base portion 112 orone or more components thereof, such as the puller 178 and the basecap180, may alternatively have different features and/or dimensions, forexample, for a medication delivery device 10 carrying a different volumeof the therapeutic agent 138, such as 2 mL of the therapeutic agent 138.

In other embodiments, other arrangements of the base portion 112 arepossible. For example, FIG. 26 illustrates an alternative shield puller182 and FIG. 27 illustrates an alternative basecap 184 that may be usedinstead of the shield puller 178 and the basecap 180, respectively. Theshield puller 182 and the basecap 184 include the same features as theshield puller 178 and the basecap 180, respectively, except that theshield puller 178 and the basecap 180 include guard-receiving features186 and 188 that, as the name implies, receive the guard features 174 ofthe baseplate 110. Illustratively, the guard-receiving features 186 and188 include a plurality of elongated slots for receiving the elongatedridges of the baseplate 110.

The medication delivery device 10 may include various alternative oradditional features. For example, the medication delivery device 10 mayinclude one or more features that facilitate unlocking the device 10. Asa specific example, the device may include a second user input (notshown—for example, a button) that is actuatable by a user to unlock thedevice 10 and permit actuation of the first user input 26. Similarly,the device may include a second user input (not shown—for example, abutton) that is actuatable by a user to activate or awaken theelectronics assembly 96. As another specific example, the user input 26may be a two-stage button that is initially depressed to unlock thedevice 10 and further depressed to actuate the device 10. As yet anotherexample, the disposable portion 14 may include a sensor (not shown) thatactivates or awakens the electronics assembly 96 upon detecting that thedistal end 18 is in contact with a patient. The electronics assembly 96may include a wireless or wired connection for operatively coupling sucha sensor to the electronic controller 98. As another specific example,the device 10 may include a cover (not shown) for inhibiting accidentalactuation of the user input 26. In some embodiments, the device 10 mayinclude one or more indicators (not shown) that change states toindicate that the device 10 is unlocked. For example, such indicatorsmay include an electronic display or one or more LEDs, such as a yellowLED that illuminates to indicate that the device 10 is locked and agreen LED that illuminates to indicate that the device 10 is unlocked.

As another example, the electronics assembly 96 may include variousalternative or additional features. As a specific example, the firstactuator 70 and/or the second actuator 72 may include sensors (notshown—for example, rotary encoder sensors) to facilitate monitoringand/or providing feedback for the positions of the frame 34 and/or theplunger 36, respectively. As another specific example, the electronicsassembly 96 may include a sensor (not shown) for determining if thedisposable portion 14 is coupled to the reusable portion 12. Such asensor may activate or “awaken” the electronics assembly 96 upondetecting that the disposable portion 14 is coupled to the reusableportion 12. As yet another example, the disposable portion 14 mayinclude an identifier (for example, an RFID transmitter or EEPROM) tofacilitate providing properties of the therapeutic agent 138 to thereusable portion 12. Such properties may include, for example, the typeand/or volume of the therapeutic agent 138 carried by the therapeuticagent delivery assembly 108. The reusable portion 12 may use theproperties of the therapeutic agent 138 to determine, for example, anappropriate rate for driving the plunger 36 and delivering thetherapeutic agent 138 to a patient.

Illustratively, a method of using the medication delivery device 10 isas follows. Referring to FIG. 28 , the medication delivery device 10 isillustrated before coupling the disposable portion 14 to the reusableportion 12. The disposable portion 14 is coupled to the reusable portion12 by coupling the securing features 126 of the disposable portion 14 tothe securing features 68 of the reusable portion 12. More specifically,the disposable portion 14 is translated relative to the reusable portion12 in a proximal direction D1 until the proximal cover 104 of thedisposable portion 14 is received in the coupling portion 64 of thereusable portion 12, and then the disposable portion 14 is rotatedrelative to the reusable portion 12 in a rotational direction R1 tosecure the L-shaped recesses of the proximal cover 104 to the L-shapedprotrusions of the reusable portion 12. The medication delivery device10 may be provided to a user before or after coupling the disposableportion 14 to the reusable portion 12.

Referring to FIG. 29 , upon coupling the disposable portion 14 to thereusable portion 12, the device 10 occupies a “loaded” or “ready”configuration. In the ready configuration, the frame 34 of the drivemechanism 22 abuts the proximal stop element 142 of the therapeuticagent delivery assembly 108 and the plunger 36 abuts the piston 134 ofthe therapeutic agent delivery assembly 108. In addition, the baseportion 112 obscures the needle 140, and the therapeutic agent deliveryassembly 108 is disposed in a stowed configuration in which the needle140 is disposed proximally relative to the distal end 18 of the device10.

Referring to FIG. 30 , the base portion 112 is next detached from thedisposable portion 14. More specifically, the base portion 112 istranslated relative to the disposable portion 14 in a distal directionD2. Upon detaching the base portion 112 from the disposable portion 14,the inner passageway 166 of the baseplate 110 is unobscured, but thetherapeutic agent delivery assembly 108 remains in the stowedconfiguration.

Referring to FIG. 31 , the device 10 is then positioned such that thedistal end 18 abuts the skin S of a patient. The user input 26 is nextactuated (illustratively, depressed in a distal direction D3 for 3seconds) to, generally, actuate the device 10 and deliver thetherapeutic agent 138 to the patient.

Referring to FIG. 32 , the electronic controller 98 (shown elsewhere)energizes the first actuator 70 to distally advance the needle 140. Morespecifically, the electronic controller 98 energizes the first motor 82,and the first motor 82 rotatably drives the first pinion 84 in arotational direction R2. The driving engagement of the first pinion 84with the first rack 48 causes the drive mechanism 22 to translaterelative to the housing 20 in a distal, first drive direction D4. Asillustrated, the first drive direction D4 may be substantially parallelto the longitudinal axis A (that is, parallel±5 degrees). The biasingelement 24 may expand to assist translating the drive mechanism 22relative to the housing 20 in the first drive direction D4. The frame 34of the drive mechanism 22 pushes the therapeutic agent delivery assembly108 in the first drive direction D4 and compresses the biasing element106. The therapeutic agent delivery assembly 108 thereby moves from thestowed configuration to a deployed configuration. In the deployedconfiguration, the needle 140 at least partially extends distally fromthe distal end 18 of the device 10 and pierces the skin S of thepatient.

Referring to FIG. 33 , the electronic controller 98 (shown elsewhere)next energizes the second actuator 72 to deliver the therapeutic agent138 to the patient. More specifically, the electronic controller 98energizes the second motor 86, the second motor 86 rotatably drives thesecond pinion 88 in a rotation direction R3. The second pinion 88translatably drives the second rack 90 and the plunger 36 relative tothe frame 34 in a distal, second drive direction D5. As illustrated, thesecond drive direction D5 may be substantially parallel to thelongitudinal axis A (that is, parallel±5 degrees). The plunger 36 pushesthe piston 134 of the therapeutic agent delivery assembly 108 in thesecond drive direction D5. The piston 134 thereby pushes the therapeuticagent 138 distally to the needle 140, and the needle 140 delivers thetherapeutic agent 138 to the patient.

Referring to FIG. 34 , the electronic controller 98 (shown elsewhere)then energizes the first actuator 70 to proximally retract the needle140. More specifically, the electronic controller 98 energizes the firstmotor 82, and the first motor 82 rotatably drives the first pinion 84 ina rotational direction R4. The driving engagement of the first pinion 84with the first rack 48 causes the drive mechanism 22 to translaterelative to the housing 20 in a proximal, first retraction direction D6.As illustrated, the first retraction direction D6 may be substantiallyparallel to the longitudinal axis A (that is, parallel±5 degrees). Thismotion of the drive mechanism 22 permits the biasing element 106 toexpand and translate the therapeutic agent delivery assembly 108 in thefirst retraction direction D6. The therapeutic agent delivery assembly108 thereby moves from the deployed configuration to a retractedconfiguration. In the retracted configuration, the needle 140 iswithdrawn from the skin S of the patient and is disposed proximallyrelative to the distal end 18 of the device 10.

Referring to FIG. 35 , the electronic controller 98 (shown elsewhere)next energizes the second actuator 72 to retract the plunger 36 from thetherapeutic agent delivery assembly 108. More specifically, theelectronic controller 98 energizes the second motor 86, the second motor86 rotatably drives the second pinion 88 in a rotation direction R5. Thesecond pinion 88 translatably drives the second rack 90 and the plunger36 relative to the frame 34 in a proximal, second retraction directionD7. As illustrated, the second retraction direction D7 may besubstantially parallel to the longitudinal axis A (that is, parallel±5degrees). The device 10 may be moved away from the skin S of the patientbefore or after retracting the plunger 36.

Referring to FIG. 36 , the disposable portion 14 may then be detachedfrom the reusable portion 12. The disposable portion 14 is detached fromthe reusable portion 12 by uncoupling the securing features 126 of thedisposable portion 14 from the securing features 68 of the reusableportion 12. More specifically, the disposable portion 14 is rotatedrelative to the reusable portion 12 in a rotational direction R6 todisengage the L-shaped recesses of the proximal cover 104 from theL-shaped protrusions of the reusable portion 12, and then the disposableportion 14 is translated relative to the reusable portion 12 in a distaldirection D8 until the proximal cover 104 of the disposable portion 14is detached from the coupling portion 64 of the reusable portion 12.

Referring to FIG. 37 , upon detaching the spent disposable portion 14from the reusable portion 12, the spent disposable portion 14 may bediscarded, and the method of using the device 10 may be repeated with afresh disposable portion 14.

While this invention has been shown and described as having preferreddesigns, the present invention may be modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

Various aspects are described in this disclosure, which include, but arenot limited to, the following aspects:

1. A medication delivery device, including: a disposable portion,including: a housing having a distal end; a therapeutic agent deliveryassembly carried by the housing, the therapeutic agent delivery assemblyincluding: a chamber including a passageway to carry a therapeuticagent; a needle in communication with the passageway; the therapeuticagent delivery assembly being translatable relative to the housing froma stowed configuration to a deployed configuration, in the stowedconfiguration the needle being disposed proximally relative to thedistal end of the housing, and in the deployed configuration the needleat least partially extending distally from the distal end of thehousing; a reusable portion detachably carrying the disposable portion,the reusable portion including: a housing; a drive mechanism carried bythe housing of the reusable portion, the drive mechanism including: afirst rack and pinion mechanism; a frame translatably carried by thehousing of the reusable portion via the first rack and pinion mechanism;a second rack and pinion mechanism coupled to the frame; a plungertranslatably carried by the frame via the second rack and pinionmechanism; the first rack and pinion mechanism being actuatable totranslate the frame relative to the housing of the reusable portion, theframe thereby translating the therapeutic agent delivery assemblyrelative to the housing of the disposable portion from the stowedconfiguration to the deployed configuration, and the second rack andpinion mechanism being actuatable to translate the plunger relative tothe frame to deliver the therapeutic agent from the needle.

2. The medication delivery device of aspect 1, wherein the medicationdelivery device is elongated along a longitudinal axis extending betweenthe disposable portion and the reusable portion, the first rack andpinion mechanism is actuatable to translate the frame relative to thehousing of the reusable portion in a drive direction, the drivedirection being substantially parallel to the longitudinal axis, and theframe thereby translating the therapeutic agent delivery assemblyrelative to the housing of the disposable portion in the drive directionand from the stowed configuration to the deployed configuration.

3. The medication delivery device of aspect 2, wherein the drivedirection is a first drive direction, and wherein the second rack andpinion mechanism is actuatable to translate the plunger relative to theframe in a second drive direction, the second drive direction beingsubstantially parallel to the longitudinal axis, and the plunger therebycausing the therapeutic agent delivery assembly to deliver thetherapeutic agent from the needle.

4. The medication delivery device of aspect 1, wherein the medicationdelivery device is elongated along a longitudinal axis extending betweenthe disposable portion and the reusable portion, the second rack andpinion mechanism is actuatable to translate the plunger relative to theframe in a drive direction, the drive direction being substantiallyparallel to the longitudinal axis, and the plunger thereby causing thetherapeutic agent delivery assembly to deliver the therapeutic agentfrom the needle.

5. The medication delivery device of any one of aspects 1-4, wherein thefirst rack and pinion mechanism includes: a motor carried by the frame;a pinion rotatably driven by the motor; and a rack carried by thehousing of the reusable portion and translatably driven by the pinion.

6. The medication delivery device of aspect 5, wherein the rack ismonolithically formed with the housing of the reusable portion.

7. The medication delivery device of aspect 5, wherein the motor is afirst motor, the pinion is a first pinion, and the rack is a first rack,and wherein the second rack and pinion mechanism includes: a secondmotor carried by the frame; a second pinion rotatably driven by thesecond motor; and a second rack carried by the plunger and translatablydriven by the second pinion.

8. The medication delivery device of any one of aspects 1-7, wherein thesecond rack and pinion mechanism includes: a motor carried by the frame;a pinion rotatably driven by the motor; and a rack carried by theplunger and translatably driven by the pinion.

9. The medication delivery device of aspect 8, wherein the rack ismonolithically formed with the plunger.

10. The medication delivery device of any one of aspects 1-9, whereinthe therapeutic agent delivery assembly is translatable relative to thehousing of the disposable portion from the deployed configuration to aretracted configuration, in the retracted configuration the needle beingdisposed proximally relative to the distal end of the housing of thedisposable portion, wherein the first rack and pinion mechanism isactuatable to translate the frame relative to the housing of thereusable portion in a retraction direction, and wherein the therapeuticagent delivery assembly further includes a biasing element, the biasingelement elongating when the first rack and pinion mechanism translatesthe frame relative to the housing of the reusable portion in theretraction direction, and the biasing element thereby translating thetherapeutic agent delivery assembly relative to the housing of thedisposable portion from the deployed configuration to the retractedconfiguration.

11. The medication delivery device of any one of aspects 1-10, whereinthe second rack and pinion mechanism is actuatable to translate theplunger relative to the frame in a drive direction, the plunger therebycausing the therapeutic agent delivery assembly to deliver thetherapeutic agent from the needle, and wherein the second rack andpinion mechanism is further actuatable to translate the plunger relativeto the frame in a retraction direction, the retraction direction beingopposite the drive direction.

12. The medication delivery device of any one of aspects 1-11, whereinthe passageway of the chamber includes a therapeutic agent.

13. A method for delivering a therapeutic agent from a medicationdelivery device to a patient, the medication delivery device including areusable portion and a disposable portion detachably carried by thereusable portion, the disposable portion carrying the therapeutic agent,the method including: positioning a distal end of the disposable portionadjacent to the skin of the patient, a needle of the disposable portionbeing disposed proximally relative to the distal end of the disposableportion; actuating a first rack and pinion mechanism of the reusableportion to thereby drive the needle relative to the distal end of thedisposable portion such that the needle at least partially extendsdistally from the distal end of the disposable portion and pierces theskin of the patient; and actuating a second rack and pinion mechanism ofthe reusable portion to thereby cause the disposable portion to deliverthe therapeutic agent from the needle to the patient.

14. The method of aspect 13, wherein actuating the first rack and pinionmechanism of the reusable portion to thereby drive the needle relativeto the distal end includes driving the needle in a drive direction, andfurther including, after actuating the second rack and pinion mechanismof the reusable portion, actuating the first rack and pinion mechanismof the reusable portion to thereby drive the needle relative to thedistal end of the disposable portion in a retraction direction such thatthe needle retracts from the skin of the patient.

15. The method of aspect 14, wherein the disposable portion is a firstdisposable portion and the therapeutic agent is a first therapeuticagent, the method further including: after actuating the second rack andpinion mechanism of the reusable portion a second time after deliveringthe first therapeutic agent from the needle to the patient, detachingthe first disposable portion from the reusable portion; and attaching asecond disposable portion to the reusable portion, the second disposableportion carrying a second therapeutic agent.

16. The method of aspect 14, wherein: actuating the first rack andpinion mechanism to drive the needle includes rotating a first pinion ina first direction; actuating the second rack and pinion mechanism todeliver the therapeutic agent from the needle includes rotating a secondpinion in a second direction; the method further including: actuatingthe first rack and pinion mechanism to retract the needle by rotatingthe first pinion in a third direction opposite the first direction; andactuating the second rack and pinion mechanism to retract a plunger ofthe reusable portion from the disposable portion by rotating the secondpinion in a fourth direction opposite the second direction.

17. A disposable portion for a medication delivery device, themedication delivery device including a reusable portion configured todetachably carry the disposable portion, the disposable portionincluding: a housing having a distal end; a therapeutic agent deliveryassembly translatably carried in the housing, the therapeutic agentdelivery assembly including: a chamber including a passageway; atherapeutic agent carried in the passageway; a needle in communicationwith the passageway; a biasing element carried in the housing, thebiasing element biasing the therapeutic agent delivery assembly toward astowed configuration, in the stowed configuration the needle beingdisposed proximally relative to the distal end of the housing; and aproximal cover carried by the housing, the proximal cover retaining thetherapeutic agent delivery assembly in the housing, and the proximalcover including a securing feature configured to detachably secure thedisposable portion to the reusable portion; the therapeutic agentdelivery assembly being translatable by the reusable portion relative tothe housing from the stowed configuration to a deployed configuration,in the deployed configuration the needle at least partially extendingdistally from the distal end of the housing.

18. The disposable portion of aspect 17, wherein the securing feature ofthe proximal cover includes a twist-to-lock connector.

19. The disposable portion of any one of aspects 17-18, wherein theproximal cover includes an inner passageway, the inner passageway beingconfigured to receive a plunger of the reusable portion and permit theplunger to translate the therapeutic agent delivery assembly from thestowed configuration to the deployed configuration.

20. The disposable portion of any one of aspects 17-19, furtherincluding a baseplate carried by the housing, the baseplate including aninner passageway that receives the therapeutic agent delivery assembly,and the baseplate further including a guard feature configured toinhibit entry of foreign objects into the inner passageway.

21. The disposable portion of aspect 20, wherein the guard featureincludes an elongated ridge.

22. The disposable portion of any one of aspects 17-21, wherein theproximal cover is weldably connected to the housing.

23. A drive portion of a medication delivery device including: ahousing; a drive mechanism carried by the housing, the drive mechanismincluding: a first rack and pinion mechanism; a frame translatablycarried by the housing via the first rack and pinion mechanism; a secondrack and pinion mechanism coupled to the frame; a plunger translatablycarried by the frame via the second rack and pinion mechanism; the firstrack and pinion mechanism being actuatable to translate the framerelative to the housing configured to translate a therapeutic agentdelivery assembly from a stowed configuration to a deployedconfiguration, and the second rack and pinion mechanism being actuatableto translate the plunger relative to the frame to deliver a therapeuticagent from a needle of the therapeutic agent delivery assembly.

24. The drive portion of aspect 23, wherein the first rack and pinionmechanism includes: a motor carried by the frame; a pinion rotatablydriven by the motor; and a rack carried by the housing of the reusableportion and translatably driven by the pinion.

25. The drive portion of aspect 24, wherein the rack is monolithicallyformed with the housing of the reusable portion.

26. The drive portion of any one of aspects 23-25, wherein the motor isa first motor, the pinion is a first pinion, and the rack is a firstrack, and wherein the second rack and pinion mechanism includes: asecond motor carried by the frame; a second pinion rotatably driven bythe second motor; and a second rack carried by the plunger andtranslatably driven by the second pinion.

27. The drive portion of aspect 26, wherein the second rack and pinionmechanism includes: a motor carried by the frame; a pinion rotatablydriven by the motor; and a rack carried by the plunger and translatablydriven by the pinion.

28. The drive portion of aspect 27, wherein the rack is monolithicallyformed with the plunger.

1. A medication delivery device, comprising: a disposable portion,comprising: a housing having a distal end; a therapeutic agent deliveryassembly carried by the housing of the disposable portion, thetherapeutic agent delivery assembly comprising: a chamber comprising apassageway to carry a therapeutic agent; a needle in communication withthe passageway; the therapeutic agent delivery assembly beingtranslatable relative to the housing of the disposable portion from astowed configuration to a deployed configuration, in the stowedconfiguration the needle being disposed proximally relative to thedistal end of the housing of the disposable portion, and in the deployedconfiguration the needle at least partially extending distally from thedistal end of the housing of the disposable portion; a reusable portiondetachably carrying the disposable portion, the reusable portioncomprising: a housing; a drive mechanism carried by the housing of thereusable portion, the drive mechanism comprising: a first rack andpinion mechanism; a frame translatably carried by the housing of thereusable portion via the first rack and pinion mechanism; a second rackand pinion mechanism coupled to the frame; a plunger translatablycarried by the frame via the second rack and pinion mechanism; the firstrack and pinion mechanism being actuatable to translate the framerelative to the housing of the reusable portion, the frame therebytranslating the therapeutic agent delivery assembly relative to thehousing of the disposable portion from the stowed configuration to thedeployed configuration, and the second rack and pinion mechanism beingactuatable to translate the plunger relative to the frame to deliver thetherapeutic agent from the needle.
 2. The medication delivery device ofclaim 1, wherein the medication delivery device is elongated along alongitudinal axis extending between the disposable portion and thereusable portion, the first rack and pinion mechanism is actuatable totranslate the frame relative to the housing of the reusable portion in adrive direction, the drive direction being substantially parallel to thelongitudinal axis, and the frame thereby translating the therapeuticagent delivery assembly relative to the housing of the disposableportion in the drive direction and from the stowed configuration to thedeployed configuration.
 3. The medication delivery device of claim 2,wherein the drive direction is a first drive direction, and wherein thesecond rack and pinion mechanism is actuatable to translate the plungerrelative to the frame in a second drive direction, the second drivedirection being substantially parallel to the longitudinal axis, and theplunger thereby causing the therapeutic agent delivery assembly todeliver the therapeutic agent from the needle.
 4. The medicationdelivery device of claim 1, wherein the medication delivery device iselongated along a longitudinal axis extending between the disposableportion and the reusable portion, the second rack and pinion mechanismis actuatable to translate the plunger relative to the frame in a drivedirection, the drive direction being substantially parallel to thelongitudinal axis, and the plunger thereby causing the therapeutic agentdelivery assembly to deliver the therapeutic agent from the needle. 5.The medication delivery device of claim 1, wherein the first rack andpinion mechanism comprises: a motor carried by the frame; a pinionrotatably driven by the motor; and a rack carried by the housing of thereusable portion and translatably driven by the pinion.
 6. Themedication delivery device of claim 5, wherein the rack ismonolithically formed with the housing of the reusable portion.
 7. Themedication delivery device of claim 5, wherein the motor is a firstmotor, the pinion is a first pinion, and the rack is a first rack, andwherein the second rack and pinion mechanism comprises: a second motorcarried by the frame; a second pinion rotatably driven by the secondmotor; and a second rack carried by the plunger and translatably drivenby the second pinion.
 8. The medication delivery device of claim 1,wherein the second rack and pinion mechanism comprises: a motor carriedby the frame; a pinion rotatably driven by the motor; and a rack carriedby the plunger and translatably driven by the pinion.
 9. The medicationdelivery device of claim 8, wherein the rack is monolithically formedwith the plunger.
 10. The medication delivery device of claim 1, whereinthe therapeutic agent delivery assembly is translatable relative to thehousing of the disposable portion from the deployed configuration to aretracted configuration, in the retracted configuration the needle beingdisposed proximally relative to the distal end of the housing of thedisposable portion, wherein the first rack and pinion mechanism isactuatable to translate the frame relative to the housing of thereusable portion in a retraction direction, and wherein the therapeuticagent delivery assembly further comprises a biasing element, the biasingelement elongating when the first rack and pinion mechanism translatesthe frame relative to the housing of the reusable portion in theretraction direction, and the biasing element thereby translating thetherapeutic agent delivery assembly relative to the housing of thedisposable portion from the deployed configuration to the retractedconfiguration.
 11. The medication delivery device of claim 1, whereinthe second rack and pinion mechanism is actuatable to translate theplunger relative to the frame in a drive direction, the plunger therebycausing the therapeutic agent delivery assembly to deliver thetherapeutic agent from the needle, and wherein the second rack andpinion mechanism is further actuatable to translate the plunger relativeto the frame in a retraction direction, the retraction direction beingopposite the drive direction.
 12. The medication delivery device ofclaim 1, wherein the passageway of the chamber includes a therapeuticagent. 13-22. (canceled)
 23. A drive portion of a medication deliverydevice comprising: a housing; a drive mechanism carried by the housing,the drive mechanism comprising: a first rack and pinion mechanism; aframe translatably carried by the housing via the first rack and pinionmechanism; a second rack and pinion mechanism coupled to the frame; aplunger translatably carried by the frame via the second rack and pinionmechanism; the first rack and pinion mechanism being actuatable totranslate the frame relative to the housing configured to translate atherapeutic agent delivery assembly from a stowed configuration to adeployed configuration, and the second rack and pinion mechanism beingactuatable to translate the plunger relative to the frame to deliver atherapeutic agent from a needle of the therapeutic agent deliveryassembly.
 24. The drive portion of claim 23, wherein the first rack andpinion mechanism comprises: a motor carried by the frame; a pinionrotatably driven by the motor; and a rack carried by the housing of thereusable portion and translatably driven by the pinion.
 25. The driveportion of claim 24, wherein the rack is monolithically formed with thehousing of the reusable portion.
 26. The drive portion of claim 24,wherein the motor is a first motor, the pinion is a first pinion, andthe rack is a first rack, and wherein the second rack and pinionmechanism comprises: a second motor carried by the frame; a secondpinion rotatably driven by the second motor; and a second rack carriedby the plunger and translatably driven by the second pinion.
 27. Thedrive portion of claim 26, wherein the second rack and pinion mechanismcomprises: a motor carried by the frame; a pinion rotatably driven bythe motor; and a rack carried by the plunger and translatably driven bythe pinion.
 28. The drive portion of claim 27, wherein the rack ismonolithically formed with the plunger.
 29. A medication deliverydevice, comprising: the drive portion of claim 23; and a disposableportion including a disposable portion housing having a distal end, atherapeutic agent delivery assembly carried by the disposable portionhousing, the therapeutic agent delivery assembly having a chambercomprising a passageway to carry a therapeutic agent, and a needle incommunication with the passageway, wherein the therapeutic agentdelivery assembly is coupled to the frame of the drive portion and istranslatable relative to the disposable portion housing from a stowedconfiguration to a deployed configuration, in the stowed configurationthe needle being disposed proximally relative to the distal end of thedisposable portion housing, and in the deployed configuration the needleat least partially extending distally from the distal end of thedisposable portion housing, wherein the plunger defines a rack that ismovable within the passageway to move a piston within the chamber. 30.The medication delivery device of claim 29, wherein therapeutic agentdelivery assembly further comprises a stop element carried by thechamber.